The results indicate that recycled concrete aggregate can be used as a coarse
aggregate in high calcium fly ash geopolymer concrete. The obtained strengths and durability
were slightly lower than those containing crushed limestone. However, geopolymer concrete
containing recycled concrete aggregate still possessed sufficiently high compressive strength
of 30.6-38.4 MPa or approximately 76-93% of the same geopolymer concretes containing
crushed limestone.